Patricia Spann told officials she didn’t think marrying Misty was illegal because her name is no longer listed on her daughter’s birth certificate, according to KFOR TV.

The fact that she wasn’t on the birth certificate is how they were able to get a marriage license.

Their marriage didn’t come to light until a Oklahoma Department of Human Services child welfare investigator did an inquiry that led her to believe that the couple was having an incestuous relationship, according to Tulsa World.

This isn’t the first time that Patricia Spann has married one of her offspring.